Background: Does demonstrating attachment to one’s nation necessarily imply that the individual is interested in the history of that nation and has a considerable knowledge about its origins? In the present paper, we examine how two forms of national identity (i.e., national narcissism vs. secure national identification) relate to individuals’ self-declared interest in their na-tion’s history. Additionally, we investigate whether this relationship can account for their tendency to overstate their knowledge. Participants and procedure: In two studies (Ntotal = 2137) conducted on a representative samples of adult Poles, we assessed two types of national identi-ty: self-declared interest in the nation’s history and objectively measured knowledge about the nation and its history through an overclaiming task. Results: We found that those who narcissistically identified with their nation overclaimed their historical knowledge. Specifically, they claimed familiarity with non-existing historical events and were unable to claim familiarity with existing ones. We also found that the relationship between national narcissism and declared interest in one’s nation’s history was effectively re-duced to zero after partialing out the shared variance to overclaiming historical knowledge. Conclusions: Our findings suggest that national narcissism might be a superficial self-presentation style, which is primarily focused on oneself, not on the nation. Those who narcissistically identify themselves with their nation only proclaim their interest, but have lower objective knowledge.